1. Field of the Invention
The present invention relates to the treatment of a natural lumen or passage located in a filled area, in particular in a solid organ of the human or animal body, which lumen provides for the transit or circulation of a fluid, in particular a body fluid, which is either liquid or gaseous, this natural lumen or passage being obstructed by the effect of a local cell proliferation.
The urinary passages, and in particular the urethra, constitute examples of natural lumina within the meaning of the present invention.
The expression “local cell proliferation” is understood to mean any biological process, for example of the benign or malignant tumor type, leading locally to a tissue excess, either organized or unorganized, and provoking an obstruction, or obstructing the natural lumen or passage in question, at the site where said proliferation develops. Benign prostatic hypertrophy, or prostatic adenoma, constitutes one example of an obstructive cell proliferation of this nature.
The present invention will be introduced, defined and described, by way of non-limiting example, with reference to the treatment of acute or chronic prostate obstructions in man.
2. Description of Related Art
It is presently known to treat prostate obstruction by mechanical means, that is to say without curative action vis-à-vis the cause of the obstruction, and for this purpose various intraurethral prostheses have been described or are available on the market. Reference will be made, by way of example, to the prosthesis which is described in document WO-A-94/18907.
Such prostheses, which are implanted permanently or temporarily, provide for only a palliative treatment of the prostate obstructions.
These prostheses may be poorly tolerated by the patient on account of their purely mechanical action, these prostheses being foreign bodies which are left in place permanently, or else temporarily but repeatedly. In some cases there may be a risk of infection and of not inconsiderable migration. These prostheses, when they are permanent, present a risk of obstruction, either by incrustation (deposition of crystals contained in the urine) or by hyperplasia inside the prosthesis, as a reaction to the foreign body which the prosthesis represents; this hyperplasia can go so far as to obstruct certain permanent prostheses.